阅读说明：本技术 一种控制方法、控制系统及电动阀 (Control method, control system and electric valve ) 是由 不公告发明人 于 2019-06-03 设计创作，主要内容包括：一种控制方法、控制系统及电动阀,控制方法包括获取实际测量的设定参数曲线；其中,设定参数曲线包括电动阀的位置与设定参数的对应关系；根据目标设定参数获取实际测量的设定参数曲线上的第一设定参数点和第二设定参数点；其中,目标设定参数大于第一设定参数点对应的设定参数且小于第二设定参数点对应的设定参数；根据第一设定参数点和第二设定参数点获取拟合线性曲线；根据目标设定参数以及拟合线性曲线获取电动阀的目标位置；控制电动阀向电动阀的目标位置运行。这样,有利于在不损失控制精度的同时,实现目标设定参数的均匀变化,提升设定参数曲线的线性度,改善设定参数波动的问题。(A control method, a control system and an electric valve are provided, wherein the control method comprises the steps of obtaining a set parameter curve of actual measurement; the setting parameter curve comprises the corresponding relation between the position of the electric valve and the setting parameter; acquiring a first set parameter point and a second set parameter point on a set parameter curve of actual measurement according to a target set parameter; the target setting parameter is larger than the setting parameter corresponding to the first setting parameter point and smaller than the setting parameter corresponding to the second setting parameter point; obtaining a fitting linear curve according to the first set parameter point and the second set parameter point; acquiring a target position of the electric valve according to the target setting parameters and the fitted linear curve; and controlling the electric valve to operate towards the target position of the electric valve. Therefore, the method is beneficial to realizing the uniform change of the target setting parameter without losing the control precision, improving the linearity of the setting parameter curve and improving the problem of the fluctuation of the setting parameter.)

1. A control method capable of controlling an electrically operated valve, characterized by comprising:

acquiring a set parameter curve of actual measurement; the set parameter curve comprises the corresponding relation between the position of the electric valve and set parameters;

acquiring a first set parameter point and a second set parameter point on the set parameter curve which are actually measured according to a target set parameter; the target setting parameter is larger than the setting parameter corresponding to the first setting parameter point and smaller than the setting parameter corresponding to the second setting parameter point;

obtaining a fitted linear curve according to the first set parameter point and the second set parameter point;

acquiring a target position of the electric valve according to the target setting parameter and the fitted linear curve;

controlling the electric valve to operate towards the target position of the electric valve.

2. The control method according to claim 1, wherein the obtaining the actually measured first and second set parameter points on the set parameter curve according to the target set parameter comprises:

the actually measured set parameter curve fluctuates periodically, the set fluctuation period of the actually measured set parameter curve is obtained according to the target set parameter, and the first set parameter point and the second set parameter point are two end points, corresponding to the set fluctuation period, on the actually measured set parameter curve respectively.

3. The control method of claim 2, wherein said obtaining a fitted linear curve from the first set of parameter points and the second set of parameter points comprises:

and taking a straight line connecting the first set parameter point and the second set parameter point as the fitted linear curve.

4. The method according to any one of claims 1 to 3, wherein the obtaining the target position of the electrically operated valve according to the target setting parameter and the fitted linear curve comprises:

and acquiring a set parameter point of which the corresponding set parameter on the fitted linear curve is equal to the target set parameter, and taking the position of the electric valve corresponding to the set parameter point as the target position of the electric valve.

5. The control method according to any one of claims 1 to 3, wherein the controlling the electric valve to operate to the target position of the electric valve comprises:

and acquiring a target driving current required for driving a stepping motor in the electric valve according to the target position of the electric valve, and adjusting the driving current output to the stepping motor to the target driving current.

6. The control method according to claim 1, further comprising, before the acquiring the actually measured set parameter curve:

acquiring a set parameter calibration interval according to whether a calibration instruction is received or not;

correspondingly, the acquiring of the actually measured set parameter curve includes acquiring the actually measured set parameter curve corresponding to the set parameter calibration interval.

7. The control method according to claim 6, wherein the upper limit value of the set parameter calibration interval is 3% of the maximum set parameter corresponding to the electric valve.

8. The control method according to claim 1, wherein the electric valve comprises an electronic expansion valve including a valve spool, the setting parameter comprises a flow rate, and the setting parameter curve comprises a correspondence relationship between a position of the valve spool and the flow rate.

9. The control method according to claim 8, wherein the electronic expansion valve further comprises a motor, the setting parameter further comprises a microstep value of the motor, the position of the valve element is determined by the microstep value of the motor, the setting parameter curve further comprises a corresponding relationship between the microstep value of the motor and a flow rate, and the electronic expansion valve is operated toward a target position by adjusting the microstep value of the motor.

10. A control method capable of controlling an electrically operated valve, characterized by comprising:

acquiring a target position of the electric valve according to target setting parameters and a fitted linear curve;

controlling the electric valve to operate towards the target position of the electric valve;

the fitting linear curve is prestored in a control system for controlling the operation of the electric valve, the fitting linear curve changes along with the change of a set parameter curve, and the set parameter curve comprises the corresponding relation between the position of the electric valve and a set parameter;

the fitting linear curve is obtained by acquiring a first setting parameter point and a second setting parameter point which are periodically changed on the setting parameter curve, acquiring a fitting linear curve section between the first setting parameter point and the second setting parameter point according to the first setting parameter point and the second setting parameter point, and connecting the fitting linear curve sections.

11. A control system capable of controlling an electrically operated valve, comprising:

the actual curve acquisition module is used for acquiring a set parameter curve of actual measurement; the set parameter curve comprises the corresponding relation between the position of the electric valve and set parameters;

the parameter point acquisition module is used for acquiring a first set parameter point and a second set parameter point on the set parameter curve which are actually measured according to a target set parameter; the target setting parameter is larger than the setting parameter corresponding to the first setting parameter point and smaller than the setting parameter corresponding to the second setting parameter point;

the fitting curve acquisition module is used for acquiring a fitting linear curve according to the first set parameter point and the second set parameter point;

a target position obtaining module, configured to obtain a target position of the electric valve according to the target setting parameter and the fitted linear curve;

and the electric valve control module is used for controlling the electric valve to operate towards the target position of the electric valve.

12. A control system capable of controlling an electrically operated valve, comprising:

the target position obtaining module is used for obtaining the target position of the electric valve according to the target setting parameters and the fitted linear curve;

the electric valve control module is used for controlling the electric valve to operate towards the target position of the electric valve;

the storage module is used for storing the fitting linear curve, the fitting linear curve changes along with the change of a set parameter curve, and the set parameter curve comprises the corresponding relation between the position of the electric valve and a set parameter; the fitting linear curve is obtained by acquiring a first setting parameter point and a second setting parameter point which are periodically changed on the setting parameter curve, acquiring a fitting linear curve section between the first setting parameter point and the second setting parameter point according to the first setting parameter point and the second setting parameter point, and connecting the fitting linear curve sections.

13. An electrically operated valve comprising a stator assembly, a rotor assembly, a valve core and a circuit board assembly, wherein the stator assembly comprises a coil, the rotor assembly comprises a permanent magnet, the coil is electrically connected with the circuit board assembly, the coil generates an excitation magnetic field after being electrified, the rotor assembly rotates in the excitation magnetic field, the position of the valve core is the position of the electrically operated valve, and the circuit board assembly is integrated with the control system according to claim 11 or 12.

Technical Field

The embodiment of the invention relates to the field of control, in particular to a control method, a control system and an electric valve.

Background

The electrically operated valve generally includes a controller, a stepping motor and a valve core, the controller sends a driving signal to the stepping motor to control the stepping motor to rotate, the stepping motor drives the valve core of the electrically operated valve to operate relative to the valve port, so that the valve port reaches a corresponding opening degree, the electrically operated valve may be, for example, an electronic expansion valve, and the adjustment of the flow rate of the working medium can be realized by adjusting the position of the valve core in the electronic expansion valve.

Generally, when a stepping motor is controlled in micro-steps, a sine step-shaped driving current is input to the stepping motor, theoretically, each micro-step of the stepping motor should have the same rotation angle under the action of the sine step-shaped driving current, the change of flow corresponding to each micro-step should be uniform, but is limited by the production process and the assembly precision of mechanical structures such as a rotor and a stator of the stepping motor, and in addition, a magnetic field generated by the rotor in the stepping motor and the matching between the rotor and the stator have deviation, so that when the stepping motor is controlled in micro-steps, the rotation angle corresponding to each micro-step is not uniform, the flow change corresponding to each micro-step is not uniform, the problem of flow fluctuation exists, and the control precision of an air conditioning system is influenced.

Disclosure of Invention

In view of this, embodiments of the present invention provide a control method, a control system, and an electrically operated valve, which are beneficial to achieving uniform change of a target setting parameter without losing control accuracy, improving linearity of a setting parameter curve, and improving the problem of fluctuation of the setting parameter.

In a first aspect, an embodiment of the present invention provides a control method, capable of controlling an electrically operated valve, where the control method includes:

acquiring a set parameter curve of actual measurement; the set parameter curve comprises the corresponding relation between the position of the electric valve and set parameters;

acquiring a first set parameter point and a second set parameter point on the set parameter curve which are actually measured according to a target set parameter; the target setting parameter is larger than the setting parameter corresponding to the first setting parameter point and smaller than the setting parameter corresponding to the second setting parameter point;

obtaining a fitted linear curve according to the first set parameter point and the second set parameter point;

acquiring a target position of the electric valve according to the target setting parameter and the fitted linear curve;

controlling the electric valve to operate towards the target position of the electric valve.

In a second aspect, an embodiment of the present invention further provides a control method, capable of controlling an electrically operated valve, where the control method includes:

acquiring a target position of the electric valve according to target setting parameters and a fitted linear curve;

controlling the electric valve to operate towards the target position of the electric valve;

the fitting linear curve is prestored in a control system for controlling the operation of the electric valve, the fitting linear curve changes along with the change of a set parameter curve, and the set parameter curve comprises the corresponding relation between the position of the electric valve and a set parameter;

the fitting linear curve is obtained by acquiring a first setting parameter point and a second setting parameter point which are periodically changed on the setting parameter curve, acquiring a fitting linear curve section between the first setting parameter point and the second setting parameter point according to the first setting parameter point and the second setting parameter point, and connecting the fitting linear curve sections.

In a third aspect, an embodiment of the present invention further provides a control system, which is capable of controlling an electrically operated valve, and includes:

the actual curve acquisition module is used for acquiring a set parameter curve of actual measurement; the set parameter curve comprises the corresponding relation between the position of the electric valve and set parameters;

the parameter point acquisition module is used for acquiring a first set parameter point and a second set parameter point on the set parameter curve which are actually measured according to a target set parameter; the target setting parameter is larger than the setting parameter corresponding to the first setting parameter point and smaller than the setting parameter corresponding to the second setting parameter point;

the fitting curve acquisition module is used for acquiring a fitting linear curve according to the first set parameter point and the second set parameter point;

a target position obtaining module, configured to obtain a target position of the electric valve according to the target setting parameter and the fitted linear curve;

and the electric valve control module is used for controlling the electric valve to operate towards the target position of the electric valve.

In a fourth aspect, an embodiment of the present invention further provides a control system, capable of controlling an electrically operated valve, where the control system includes:

the target position obtaining module is used for obtaining the target position of the electric valve according to the target setting parameters and the fitted linear curve;

the electric valve control module is used for controlling the electric valve to operate towards the target position of the electric valve;

the storage module is used for storing the fitting linear curve, the fitting linear curve changes along with the change of a set parameter curve, and the set parameter curve comprises the corresponding relation between the position of the electric valve and a set parameter; the fitting linear curve is obtained by acquiring a first setting parameter point and a second setting parameter point which are periodically changed on the setting parameter curve, acquiring a fitting linear curve section between the first setting parameter point and the second setting parameter point according to the first setting parameter point and the second setting parameter point, and connecting the fitting linear curve sections.

In a fifth aspect, an embodiment of the present invention further provides an electrically operated valve, including a stator assembly, a rotor assembly, a valve core, and a circuit board assembly, where the stator assembly includes a coil, the rotor assembly includes a permanent magnet, the coil is electrically connected to the circuit board assembly, the coil generates an excitation magnetic field after being energized, the rotor assembly rotates in the excitation magnetic field, the position of the valve core is the position of the electrically operated valve, and the circuit board assembly is integrated with the control system according to the third aspect or the fourth aspect.

The embodiment of the invention provides a control method, a control system and an electric valve, wherein the control method comprises the steps of obtaining a set parameter curve which is actually measured and comprises the corresponding relation between the position of the electric valve and a set parameter, obtaining a first set parameter point and a second set parameter point on the set parameter curve which is actually measured according to a target set parameter, obtaining a set parameter which is larger than the set parameter corresponding to the first set parameter point and is smaller than the set parameter corresponding to the second set parameter point, obtaining fitting linearity according to the first set parameter point and the second set parameter point, obtaining the target position of the electric valve according to the target set parameter and the fitting linear curve, controlling the electric valve to run to the target position of the electric valve, namely obtaining the target position of the electric valve corresponding to the target set parameter by using the fitting linear curve determined by the first set parameter point and the second set parameter point, and the electric valve is controlled to operate towards a target position, so that uniform change of target setting parameters is realized without loss of control precision, the linearity of a setting parameter curve is improved, and the problem of fluctuation of the setting parameters is solved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments or the background art of the present invention, the drawings needed to be used in the description of the embodiments or the background art will be briefly introduced below, and it is obvious that the drawings in the following description are schematic diagrams of some embodiments of the present invention, and for those skilled in the art, other solutions can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic flow chart of a first control method according to an embodiment of the present invention;

fig. 2 is a schematic diagram of a relationship curve between a sine value of a current angle and a micro-step number of a stepping motor according to an embodiment of the present invention;

fig. 3 is a schematic diagram of a set parameter curve according to an embodiment of the present invention;

fig. 4 is a schematic flowchart of a second control method according to an embodiment of the present invention;

fig. 5 is a schematic flowchart of a third control method according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of another setting parameter curve according to an embodiment of the present invention;

FIG. 7 is a schematic block diagram of a first control system provided in accordance with an embodiment of the present invention;

fig. 8 is a schematic structural diagram of an electrically operated valve according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described through embodiments with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Fig. 1 is a schematic flowchart of a first control method provided in an embodiment of the present invention, where the control method may be applied to a scenario where an electric valve needs to be controlled, and may be executed by a control system of the electric valve, where the control system may be executed in a software and/or hardware manner. As shown in fig. 1, the control method includes:

s101, acquiring a set parameter curve of actual measurement; the setting parameter curve comprises the corresponding relation between the position of the electric valve and the setting parameter.

And acquiring a set parameter curve of actual measurement, wherein the set parameter curve comprises the corresponding relation between the position of the electric valve and the set parameter. For example, the electric valve may be an electronic expansion valve, the setting parameter may include a flow rate, and the curve of the setting parameter may include a corresponding relationship between a position of the electronic expansion valve and the flow rate.

The electric valve generally comprises a controller, a stepping motor and a valve core, wherein the controller sends a driving signal to the stepping motor to control the stepping motor to rotate, the stepping motor drives the valve core of the electric valve to move relative to the valve port to enable the valve port to reach corresponding opening degree, the position of the electric valve can be understood as the position of the valve core of the electric valve, and the position of the valve core of the electric valve, the opening area of the valve port of the electric valve and the microstep number of the stepping motor are in linear relation, so that the position of the electric valve can be represented by the microstep number of the stepping motor in the electric valve.

Fig. 2 is a schematic view of a relationship curve between a sine value of a current angle and a micro-step number of a stepping motor according to an embodiment of the present invention, fig. 3 is a schematic view of a set parameter curve according to an embodiment of the present invention, an abscissa in fig. 2 represents the micro-step number of the stepping motor, an ordinate represents the sine value of the current angle corresponding to a current input to a stator in the stepping motor, an abscissa in fig. 3 represents the micro-step number of the stepping motor, and an ordinate represents a set parameter, the set parameter may be, for example, a flow rate, and the micro-step number of the stepping motor may represent a position of an electric valve, so the curve shown in fig. 3 may represent the set parameter curve and includes a corresponding relationship between a position of the electric valve and the set parameter.

The sinusoidal stepped current shown by the curve a1 in fig. 2 may be used to drive the stepping motor to rotate, accordingly, the obtained actually measured setting parameter curve is shown as the curve b1 in fig. 3, in addition, the position of 96 micro steps corresponds to one whole step of the stepping motor, fig. 3 exemplarily shows the actually measured setting parameter curve obtained within one whole step range, and it can be seen that the actually measured setting parameter curve b1 has large fluctuation and is not smooth as a whole.

S102, acquiring a first set parameter point and a second set parameter point on a set parameter curve of actual measurement according to a target set parameter; the target setting parameter is larger than the setting parameter corresponding to the first setting parameter point and smaller than the setting parameter corresponding to the second setting parameter point.

And acquiring a first setting parameter point and a second setting parameter point on a setting parameter curve of actual measurement according to the target setting parameter, wherein the target setting parameter is greater than the setting parameter corresponding to the first setting parameter point and less than the setting parameter corresponding to the second setting parameter point.

Optionally, the actually measured set parameter curve fluctuates periodically, the set fluctuation period of the actually measured set parameter curve is obtained according to the target set parameter, and the first set parameter point and the second set parameter point are two endpoints of the actually measured set parameter curve corresponding to the set fluctuation period, respectively. As shown in fig. 3, the actually measured set parameter curve is a curve b1, and the curve b1 fluctuates periodically, it should be noted that the curve b1 fluctuates periodically does not limit the trend of the curve b1 to have strict periodicity, and the curve b1 appears convex and concave periodically, that is, the curve b1 fluctuates periodically according to the embodiment of the present invention.

The setting fluctuation period of the actually measured setting curve is obtained according to the target setting parameter, the setting fluctuation period of the actually measured setting parameter curve can be determined according to the size of the target setting parameter, the setting parameter corresponding to one end point of the actually measured setting curve corresponding to each fluctuation period is smaller than the target setting parameter, the fluctuation period of the other end point corresponding to the setting parameter larger than the target setting parameter is the setting fluctuation period, and the first setting parameter point and the second setting parameter point are two end points on the actually measured setting parameter curve corresponding to the setting fluctuation period respectively.

For example, the set fluctuation cycle of the actually measured set parameter curve may be set to the fluctuation cycle a1 shown in fig. 3, and the end points corresponding to the fluctuation cycle a1 are set to the first set parameter point and the second set parameter point, respectively. Specifically, the setting parameter L, the position of the electric valve Q, the target setting parameter Lj, the first setting parameter point Pi-1 and the second setting parameter point Pi on the actually measured setting parameter curve b1 are set such that the target setting parameter Lj is greater than the ordinate corresponding to the first setting parameter point Pi-1 and less than the ordinate corresponding to the second setting parameter point Pi, the coordinates corresponding to Pi-1 may be set to (Qi-1, Li-1), the coordinates corresponding to Pi may be (Qi, Li), and then Lj is greater than Li-1 and less than Li, as shown in fig. 3.

S103, obtaining a fitting linear curve according to the first set parameter point and the second set parameter point.

And acquiring a fitting linear curve according to the acquired first set parameter point and the acquired second set parameter point. Illustratively, a straight line connecting the first set-parameter point and the second set-parameter point may be taken as the fitted linear curve.

And S104, acquiring the target position of the electric valve according to the target setting parameters and the fitted linear curve.

And acquiring the target position of the electric valve according to the target setting parameters and the fitted linear curve. For example, a set parameter point where a set parameter corresponding to the fitted linear curve is equal to a target set parameter may be obtained, and a position of the electric valve corresponding to the set parameter point may be used as a target position of the electric valve.

The target position of the electric valve corresponding to the target setting parameter Lj can be set to be Qj, then the target position of the electric valve can be determined to be Qj according to the first setting parameter point Pi-1(Qi-1, Li-1) and the second setting parameter point Pi (Qi, Li) on the fitted linear curve, and the slope calculated on the fitted linear curve according to the second setting parameter point Pi (Qi, Li) and the first setting parameter point Pi-1(Qi-1, Li-1) is equal to the slope calculated according to the target setting parameter point (Qj, Lj) and the second setting parameter point Pi (Qi, Li), and the formula is as follows:

therefore, the target position Qj of the electric valve satisfies the following calculation formula:

accordingly, the target position of the electric valve is obtained according to the fitted linear curve and the target setting parameter, the actually measured set parameter curve is corrected according to the method, the first set parameter point and the second set parameter point are respectively two end points on the actually measured set parameter curve corresponding to the set fluctuation period, a straight line connecting the first set parameter point and the second set parameter point is used as the fitted linear curve, namely, a curve b1 between the two end points of the set fluctuation period A1 is drawn into a straight line b2, the target setting parameter point (Qj, Lj) obtained according to the method is inevitably positioned on the straight line b2, and the linearity of the corrected set parameter curve can be improved by performing the processing on each set parameter point on the actually measured set parameter curve. As can be seen from fig. 3, the obtained corrected setting parameter curve is shown as a curve b2 in fig. 3, and the linearity of the corrected setting parameter curve b2 is significantly improved and the fluctuation of the setting parameter is reduced compared with the actually measured setting parameter curve b1 before correction.

And S105, controlling the electric valve to operate to the target position of the electric valve.

And controlling the electric valve to operate to the target position of the electric valve according to the acquired target position of the electric valve. For example, a target driving current required for driving the stepping motor in the electric valve can be obtained according to the target position of the electric valve, and the driving current output to the stepping motor is adjusted to the target driving current.

Specifically, the target position of the electrically operated valve may be represented by the micro step number of the stepping motor in the electrically operated valve or the rotation angle of the stepping motor, and both the micro step number of the stepping motor and the rotation angle of the stepping motor depend on the driving current output to the stepping motor, and the target driving current required for driving the stepping motor in the electrically operated valve may be obtained according to the target position of the electrically operated valve, that is, the driving current required for driving the electrically operated valve to operate to the target position and how much driving current needs to be output to the stepping motor in the electrically operated valve is obtained first, for example, a relation curve between the sine value of the current angle and the micro step number of the stepping motor obtained according to the method described in the above embodiment is shown as a curve a2 in fig. 2, the driving current output to the stepping motor is adjusted to the target driving current, that is, the driving current output to the stepping motor may be adjusted to meet the, and driving the electric valve to run to the target position through the stepping motor.

TABLE 1 correspondence between position of electrically operated valve before correction and setting parameter

TABLE 2 corresponding relationship between position of corrected electric valve and setting parameter

Table 1 shows a corresponding relationship between the position of the electrically operated valve and the setting parameter before the position of the electrically operated valve is modified by the control method provided by the embodiment of the present invention, table 2 shows a corresponding relationship between the position of the electrically operated valve and the setting parameter after the position of the electrically operated valve is modified by the control method provided by the embodiment of the present invention, both tables 1 and 2 use the rotation angle of the stepping motor in the electrically operated valve to represent the position of the electrically operated valve, and compare tables 1 and 2, before the modification, although the stepping motor in the electrically operated valve is driven to rotate according to the uniform angle, the corresponding setting parameter, such as the variation of the flow rate, is not uniform due to the production process and the assembly accuracy of the mechanical structures, such as the rotor and the stator, of the stepping motor, and the deviation of the magnetic field generated by the rotor in the stepping motor and the fit between the. By adopting the control method provided by the embodiment of the invention, the target setting parameters can be set to be uniformly changed, the target position of the electric valve can be obtained according to the set target setting parameters, for example, the target rotation angle of the stepping motor in the electric valve can be obtained, and the uniformly changed target setting parameters can be finally obtained although the rotation angle corresponding to each micro step of the stepping motor is different.

Therefore, a fitting linear curve is obtained according to the first setting parameter point and the second setting parameter point, after the target position of the electric valve is determined according to the target setting parameter and the fitting linear curve, the electric valve is driven according to the determined target position of the electric valve, the position which can be actually reached by the electric valve is basically overlapped with the target position of the electric valve, the change of the actually set parameter is basically close to linear change, the micro-step number of the stepping motor is not lost in the control process, the uniform change of the target setting parameter is favorably realized while the control precision is not lost, the linearity of the setting parameter curve is improved, and the problem of the fluctuation of the setting parameter is solved.

Fig. 4 is a flowchart illustrating a second control method according to an embodiment of the present invention. On the basis of the control method shown in fig. 1, before the set parameter curve of the actual measurement is obtained, the set parameter calibration interval may also be obtained according to whether a calibration instruction is received, and accordingly, obtaining the set parameter curve of the actual measurement includes obtaining the set parameter curve of the actual measurement corresponding to the set parameter calibration interval. As shown in fig. 4, the control method includes:

s201, acquiring a set parameter calibration interval according to whether a calibration instruction is received.

Before the set parameter curve of actual measurement is obtained, the set parameter calibration interval can be obtained according to whether a calibration instruction is received or not. For example, the set parameter calibration interval may be set to correspond to a stage from the start of the operation of the electric valve to the time when the flow rate corresponding to the electric valve is 3% of the maximum flow rate, and since the electric valve has a set parameter in a small opening range, for example, in 15 whole steps after the occurrence of the valve opening pulse, for example, the fluctuation of the flow rate is large, the set parameter calibration interval may be set to correspond to the small opening range of the electric valve, for example, the set parameter calibration interval may be set to correspond to 15 whole steps after the occurrence of the valve opening pulse.

S202, acquiring a set parameter curve of actual measurement corresponding to a set parameter calibration interval; the setting parameter curve comprises the corresponding relation between the position of the electric valve and the setting parameter.

The set parameter curve of the actual measurement can be obtained, the set parameter curve of the actual measurement corresponding to the set parameter calibration interval can be obtained, similarly, the electric valve can be set to comprise a water valve, the set parameter comprises flow, and the set parameter curve of the actual measurement corresponding to the set parameter calibration interval can comprise the corresponding relation between the position and the flow of the actual measurement water valve corresponding to the set parameter calibration interval.

S203, acquiring a first set parameter point and a second set parameter point on a set parameter curve of actual measurement according to a target set parameter; the target setting parameter is larger than the setting parameter corresponding to the first setting parameter point and smaller than the setting parameter corresponding to the second setting parameter point.

And S204, acquiring a fitting linear curve according to the first set parameter point and the second set parameter point.

And S205, acquiring the target position of the electric valve according to the target setting parameters and the fitted linear curve.

And S206, controlling the electric valve to operate to the target position of the electric valve.

Before the set parameter curve of actual measurement is obtained, the set parameter calibration interval is obtained according to whether a calibration instruction is received or not, and then the set parameter curve of actual measurement corresponding to the set parameter calibration interval is obtained, namely, the set parameter curve in the set parameter calibration interval needing to be adjusted is only corrected, so that the efficiency of correcting the set parameter curve is improved.

Fig. 5 is a flowchart illustrating a third control method according to an embodiment of the present invention. The control method can be applied to a scene needing to control the electric valve, and can be executed by a control system of the electric valve, and the control system can be executed in a software and/or hardware mode. As shown in fig. 5, the control method includes:

s301, acquiring a set parameter curve of actual measurement; the setting parameter curve comprises the corresponding relation between the position of the electric valve and the setting parameter.

And acquiring a set parameter curve of actual measurement, wherein the set parameter curve comprises the corresponding relation between the position of the electric valve and the set parameter. For example, the electric valve may include an electronic expansion valve including a valve core, the setting parameter includes a flow rate, and the setting parameter curve includes a corresponding relationship between a position of the valve core and the flow rate. The position of the electric valve can be understood as the position of a valve core of the electric valve, and the position of the valve core of the electric valve, the opening area of a valve port of the electric valve and the micro-step number of the stepping motor are all in a linear relation, so that the position of the electric valve can be represented by the micro-step number of the stepping motor in the electric valve.

For example, the electronic expansion valve may further include a motor, the setting parameter may further include a micro-step value of the motor, the position of the valve element is determined by the micro-step value of the motor, the setting parameter curve further includes a corresponding relationship between the micro-step value of the motor and a flow rate, and the electronic expansion valve is operated toward a target position by adjusting the micro-step value of the motor.

Fig. 6 is a schematic diagram of another setting parameter curve according to an embodiment of the present invention. As shown in fig. 6, the abscissa represents the number of micro steps of the stepping motor, the ordinate represents the setting parameter, the setting parameter may be, for example, the flow rate, and the number of micro steps of the stepping motor may represent the position of the electric valve, so the curve shown in fig. 6 may represent the setting parameter curve, including the corresponding relationship between the position of the electric valve and the setting parameter, and the curve c1 in fig. 6 is the actually measured setting parameter curve, and it can be seen that the actually measured setting parameter curve c1 has large fluctuation and unsmooth curve as a whole.

S302, acquiring reference setting parameters according to a setting parameter curve of actual measurement; wherein, the reference setting parameter is equal to a% of the ratio of the total setting parameter corresponding to the actually measured setting parameter curve to the position variation value of the electric valve.

Acquiring reference setting parameters according to a setting parameter curve actually measured; wherein, the reference setting parameter is equal to a% of the ratio of the total setting parameter corresponding to the actually measured setting parameter curve to the position variation value of the electric valve.

For example, the total flow rate may be L, that is, the difference between the ordinate corresponding to the end point setting parameter point and the ordinate corresponding to the start point setting parameter point on the curve c1 is L, the position variation value of the electrically operated valve corresponding to the actually measured setting parameter curve is a, that is, the number of microsteps from the start point setting parameter point to the end point setting parameter point in fig. 6 is a, that is, the difference between the abscissa corresponding to the end point setting parameter point and the abscissa corresponding to the start point setting parameter point on the curve c1 is a, and a% of the ratio of L to a is the reference setting parameter Δ L. Illustratively, a% is 6% or more and 14% or less.

And S303, deleting part of setting parameter points on the actually measured setting parameter curve according to the reference setting parameter to form a corrected setting parameter curve.

After the reference setting parameter Δ L is determined, a correction setting parameter curve can be formed by deleting a part of the setting parameter points on the actually measured setting parameter curve according to the reference setting parameter. Specifically, the difference between the vertical coordinates corresponding to each two adjacent set parameter points on the actually measured set parameter curve c1 may be obtained, the correction set parameter curve may be formed by deleting the set parameter point on the actually measured set parameter curve c1 where the difference between the vertical coordinate corresponding to the previous adjacent set parameter point and the vertical coordinate corresponding to the previous adjacent set parameter point is smaller than the reference set parameter point Δ L, and the formed correction set parameter curve is as shown by a curve c2 in fig. 6, it can be seen that the linearity of the correction set parameter curve c2 is obviously improved and the fluctuation of the set parameter is reduced compared with the actually measured set parameter curve c1 before the correction.

And S304, controlling the operation of the electric valve according to the corrected set parameter curve.

The electric valve is controlled to operate according to the corrected set parameter curve, for example, the target driving current required by the stepping motor in the electric valve can be obtained according to the change rule of the set parameter corresponding to each micro-step point on the corrected set parameter curve, and the driving current output to the stepping motor is adjusted to the target driving current, so that the change of the set parameter corresponding to the electric valve accords with the change rule of the corrected set parameter curve. Therefore, the uniform change of the set parameters of the electric valve is facilitated, the linearity of the set parameter curve is improved, and the problem of fluctuation of the set parameters is solved.

The embodiment of the invention also provides a control system which can control the electric valve. Fig. 7 is a schematic block diagram of a first control system according to an embodiment of the present invention, as shown in fig. 7, the control system includes an actual curve obtaining module 401, a parameter point obtaining module 402, a fitting curve obtaining module 403, a target position obtaining module 404, and an electric valve control module 405, the actual curve obtaining module 401 is configured to obtain a set parameter curve of actual measurement, the set parameter curve includes a corresponding relationship between a position of an electric valve and a set parameter, the parameter point obtaining module 402 is configured to obtain a first set parameter point and a second set parameter point on the set parameter curve of actual measurement according to the target set parameter, the target set parameter is greater than the set parameter corresponding to the first set parameter point and less than the set parameter corresponding to the second set parameter point, the fitting curve obtaining module 403 is configured to obtain a fitting linear curve according to the first set parameter point and the second set parameter point, the target position obtaining module 404 is configured to obtain a target position of the electric valve according to the target setting parameter and the fitted linear curve, and the electric valve control module 405 is configured to control the electric valve to operate to the target position of the electric valve.

The control system provided by the embodiment of the invention is also beneficial to realizing the uniform change of the target setting parameter, improving the linearity of the setting parameter curve and solving the problem of fluctuation of the setting parameter while the control precision is not lost.

The embodiment of the invention also provides an electric valve, and fig. 8 is a schematic structural diagram of the electric valve provided by the embodiment of the invention. As shown in fig. 8, the electric valve 100 includes a housing 60, a stator assembly 601, a rotor assembly 602, a valve core 603, and a circuit board assembly 90, the circuit board assembly 90 is disposed in an inner cavity formed by the housing 60, the stator assembly 601 is disposed at an outer periphery of the rotor assembly 602, the rotor assembly 602 and the stator assembly 601 form a stepping motor in the electric valve 100, the stator assembly 601 includes a coil, the rotor assembly 602 includes a permanent magnet, the coil is electrically connected to the circuit board assembly 90, the coil generates an excitation magnetic field after being energized, the rotor assembly 602 operates in the excitation magnetic field, the stepping motor drives the valve core 603 of the electric valve to move relative to the valve port 604, so that the valve port 604 reaches a corresponding opening degree, the position of the valve core 603 is a position of the electric valve, and. The control system of the above embodiment is integrated in the circuit board assembly, so that the control system also has the beneficial effects of the above embodiment, and details are not described here.

A fourth embodiment of a control method capable of controlling an electrically operated valve, the control method comprising obtaining a target position of the electrically operated valve from target setting parameters and a fitted linear curve; controlling the electric valve to operate to the target position of the electric valve; the fitting linear curve is prestored in a control system for controlling the operation of the electric valve, the fitting linear curve changes along with the change of the set parameter curve, and the set parameter curve comprises the corresponding relation between the position of the electric valve and the set parameter; the fitting linear curve is obtained by obtaining a first setting parameter point and a second setting parameter point which are periodically changed on a setting parameter curve, obtaining a fitting linear curve section between the first setting parameter point and the second setting parameter point according to the first setting parameter point and the second setting parameter point, and connecting the fitting linear curve sections.

The fourth control method embodiment differs from the first, second and third control method embodiments mainly in that: the fitting linear curve is prestored in a control system of the control electric valve, the fitting linear curve changes along with the change of the set parameter curve, and under the condition that the set parameter curve is not changed, the obtaining process of the fitting linear curve in the implementation mode of the first control method, the second control method and the third control method is not needed, so that the control electric valve is beneficial to batch production. The control method is thus simpler and the control system requires less space, wherein if the set parameter curve is changed, the fitted linear curve can be changed on-line or off-line, wherein the correction on-line is the same as in the first, second and third embodiments of the control method and the correction off-line is the same as in the fourth embodiment.

The embodiment of the invention also provides a second control system which can control the electric valve, wherein the control system comprises a target position acquisition module, an electric valve control module and a storage module, the target position acquisition module is used for acquiring the target position of the electric valve according to target setting parameters and a fitting linear curve, the electric valve control module is used for controlling the electric valve to operate towards the target position of the electric valve, the storage module stores the fitting linear curve, the fitting linear curve changes along with the change of the setting parameter curve, and the setting parameter curve comprises the corresponding relation between the position of the electric valve and the setting parameters; the fitting linear curve is obtained by obtaining a first setting parameter point and a second setting parameter point which are periodically changed on a setting parameter curve, obtaining a fitting linear curve section between the first setting parameter point and the second setting parameter point according to the first setting parameter point and the second setting parameter point, and connecting the fitting linear curve sections.

The main differences between the embodiment of the second control system compared to the embodiment of the first control system are: under the condition that the set parameter curve is not changed, the fitting linear curve does not need to be changed, namely, the actual curve acquisition module 401, the parameter point acquisition module 402, the fitting curve acquisition module 403 and the storage module for setting the fitting linear curve are not needed for storing the fitting linear curve, and if the set parameter curve is not changed, the fitting linear curve does not need to be changed, so that the batch production is facilitated. Wherein if the set parameter curve changes, the modification of the corrected set parameter curve can be performed on-line or off-line, wherein the on-line correction process is the same as the implementation of the first control system, and wherein the off-line correction process is the same as the implementation of the second control system.

It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments illustrated herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.